From the windows to the walls
January 28, 2024 5:51 PM   Subscribe

I find myself in sudden and unfortunate possession of a house. The double glazed windows are about thirty years old and very drafty. I do not intend to replace the windows but need to get the breeze to stop blowing through the house.

I think the draft is coming from between the window and the wall rather than from the seals on the window. Is there something I can do? I am considering insulation film on the glass itself and to check the seals of the window parts that open, but the part around the frame I am less sure about. Can I tape this with something or use silicone caulk or expander foam or similar?

I am vaguely aware that one shouldn’t seal a house entirely airtight but we’ve plenty of air coming in the chimney, up through the floor boards, etc. The home is from the fifties and is in Europe.
I expect to sell the house in the next year or two and the new owners can choose new windows for themselves, this is a stop gap measure to keep the heat in and drop heating bills mean time.
posted by Iteki to Home & Garden (9 answers total) 2 users marked this as a favorite
 
There’s a kind of grey putty that comes in coils that we use for this in the US. It’s not very sticky, so it comes off again in spring (usually). Gaps too wide for that I’d put strips of closed cell foam in.

When the moving air is stopped up, taping a single sheet of plastic over the inside keeps a lot of warmth in. We can get kits with double sided tape, plastic a big larger than window sizes, it will shrink smooth with a hairdryer. Or sheets of bubble wrap pressed on work.
posted by clew at 6:13 PM on January 28, 2024


If the gaps are small enough for caulk (I think the maximum width you can caulk is something like half a centimetre), I would use a white latex-based caulk rather than silicone. Latex-based caulk can be painted and is way easier to clean up; it's also less fussy about what it will stick to than silicone. I did this around our windowframes several years ago and it was pretty easy. Get a "caulk gun" (bracket with a squeezy handle and plunger that your tubes of caulk go in) and one of those wedge-shaped tools for scraping off the extra caulk, and have a roll of paper towels ready.
posted by heatherlogan at 7:00 PM on January 28, 2024


There’s a kind of grey putty that comes in coils

Is that butyl tape?
posted by azpenguin at 8:26 PM on January 28, 2024


Thermal curtains will help a lot. Even if it's just cheapo thick curtains hung up with tension rods (not air tight at all), it will cut down on the draft considerably and the heat loss through the windows. Some of the issue is the cold air getting into the house, some of the issue is the warm air leaking out of the house (through actual air movement or conduction by the glass). P.S. Here's a short video on heat transfer.
posted by spamandkimchi at 9:33 PM on January 28, 2024 [1 favorite]


Best answer: Grey putty Mortite caulk, made by Frost King: a product that doesn’t seem to have changed for fifty years.
posted by clew at 1:18 AM on January 29, 2024 [4 favorites]


Get a smoke pen, so you can see where drafts are coming from and going to, before you start this exercise.

The advice above is solid.
posted by mhoye at 6:33 AM on January 29, 2024 [3 favorites]


I'm assuming there's pieces of wood trim around the window. Can you share a picture? I'm not as familiar with what's common in Europe. If (but this is a fairly big if) you're comfortable pulling off the trim around the window, you'll be able to get a much better idea of how big the gap between the window and the framing is and how drafty it is.

Ideally you'll want to seal that gap somehow. If you really don't want to pull the trim off, then you'll need to do something like caulk around the trim to create a seal, but it will be more effective to seal the actual gap behind the trim. Here's a couple videos to show what you can do:

https://www.youtube.com/watch?v=heizjoK2cHA
https://www.youtube.com/watch?v=Y1Rml0uLXNs

editing to add: if you end up using the expanding foam, I'd highly recommend buying a reusable dispensing gun and using the cans that screw onto it. It's like 100 times easier to control where the foam goes and to dispense the correct amount. You'll also need the acetone/solvent cleaner so you can clean the dispensing gun after you use up the can of foam. If you buy the disposable can with the straw, it keeps expanding inside the straw even after you stop dispensing the foam, and in my experience it's just a terrible mess.
posted by Quiscale at 8:15 AM on January 29, 2024


A hard second to Quiscale's advice, with one note. Expanding foam is available in a "windows and doors" formulation. It expands, but not as wildly as the regular stuff, so as not to compress the surrounding space so much your window won't open.
posted by kate4914 at 10:29 AM on January 29, 2024


Response by poster: This is all very useful thanks! The windows are PVC clad aluminium as is common here. I am going to get some E or P profile to do inside the windows that open, and then use some of that grey caulk along the edge of the frame!
posted by Iteki at 2:36 PM on January 29, 2024 [1 favorite]


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